* Prices may differ from that shown
It's unusable. Period.
The user interface is the most counterintuitive thing I have seen ever since I dropped my historical Motorola mobile into the bin about 15 years ago (they got better since, I heard...). The connection between buttons and screen is not clear. You keep picking up your collegue's calls, because if you dial and another call comes in in the same workgroup, the OK button picks up the call rather than dialing the number in your display.
What is really absurd: There's a huge display - and no phone book... the sole purpose of this display is to show caller information, and ridiculously complicated configuration screens.
It's lucky, this phone - property of my employer, so not at risk of being flung against the wall (although smart Siemens obviously expected this reaction to it, and built it like a tank). But it definitely is one of the worst pieces of UI design I ever had to live with.
We also recently had these installed at work - they are the most terrible VoIP phones I've ever experienced. My colleagues and I have had great difficulty with phones not ringing, calls getting dropped in transfer and phones not picking up calls! Although the phone handsets are built perfectly well (and I quite like the touch to hangup feature, as opposed to a mechanical hangup), they are not intuitive at all. In fact, I consider them to be extremely difficult to use, and I am a bit of a techno geek. The most irritating thing is that although the handsets have caller display, the numbers that are displayed have no relevance - they're not recognisable as extensions in my company. Calls transferred to me don't appear with the original callers number. You'd expect a company phonebook to be in the system, with every employees name so you could tell exactly who was calling you, and at the same time, could easily search for and call your colleagues. It appears that only a select few of my colleagues have this feature! A terrible VoIP phone, a massive comedown from the Cisco system we used at my previous employer.
Recently we had these phones installed at work, they decided as a cost-cutting measure to switch to VOIP phones, replacing a phone system that worked effectively without any fuss...
...This handset who people in my office nickname 'The Star Trek Phone', although it looks good, has caused nothing but problems since its installation. The interface is confusing to control, with ambiguous on-screen instructions, phone calls routinely are cut off part way through a call, or even worse my phone chooses not to ring and directs callers straight through to voicemail after an engaged tone.
The siemens phones were even installed by siemens (they should know how to handle their own product), but they are still causing constant problems both for myself and for my colleagues. Couple this with the phone's shared use of the broadband connection slowing down the general running of my workstation, it has unfortunately not been a welcome addition to my working day.
I have to say however, that I have used VOIP phones in the past in other offices, and they were a dream to use, I just feel this handset is an inferior offering on what is an exciting development in modern telecommunication, and careful consideration should be made before purchasing it for your office or business.